MCP server

The Molpha MCP server lets an AI agent derive source IDs, run signing rounds, pay for them, publish results to Solana and build verifier calls for EVM and Starknet, all as structured tools instead of prompt glue. It speaks the Model Context Protocol and works with Claude, Cursor, VS Code, Codex and other MCP clients.

Choose an integration

	Hosted: `mcp.molpha.io`	Local: stdio
Install	Nothing. Add the URL to your client.	`npx -y @molpha/mcp`, Node.js 24 or later
Who signs	Your own wallet. The server holds no key.	A signer the server holds: local keypair, Privy or Turnkey
Subscription rounds	Sign in with your wallet (SIWX), then run rounds	One call
x402 rounds	Prepare, sign the USDC transfer, execute	One call
Spending limits	Your wallet’s own policy, plus the server’s per-round x402 price cap	Dry-run lock plus per-round and daily caps
Private API secrets	Not supported	Supported on subscription rounds
Best for	Getting started; agents that bring their own wallet	Unattended agents; private API sources

Both run the same server code and return the same signed artifacts.

Tools at a glance

Tool	What it does	Hosted	Local
`get_capabilities`	Network, registry, nodes, chains, verifier addresses, limits	✓	✓
`derive_source_id`	`sourceId` and canonical JSON for an `apiConfig`	✓	✓
`describe_feed`, `get_latest_value`	Read a Solana `Feed` account	✓	✓
`describe_access`	Is a wallet a subscription owner or delegate, and its limits	✓	✓
`get_x402_status`	x402 price quote, payee and the payer’s USDC balance	✓	✓
`list_providers`, `get_provider`, `quote_source_payment`	Integrated data providers and paywalled sources	✓	✓
`build_verifier_calldata`	EVM or Starknet `verify()` arguments (builds calldata only; verifies nothing)	✓	✓
`execute_subscription_round`	Round paid from a subscription	after sign-in	✓
`execute_x402_round`	Round paid per request with x402	after `prepare_x402_round`	✓
`submit_attestation`	Write an attestation to Solana	as `prepare_submit_attestation` + `send_signed_transaction`	✓
`begin_session`, `complete_session`	Sign in with your wallet (SIWX)	✓	—

Inputs, outputs and error codes are in the tool reference.

How it fits together

The server is an adapter and a policy boundary, not a source of truth. Every round tool returns the signed attestation plus ready-made verifier arguments for each chain you ask for. Treat that attestation, not the agent’s summary of it, as the trust anchor.

Safety model

Every round spends. There is no idempotency key: a repeated call after an unclear error is a new round. Read state (describe_feed, get_x402_status) before retrying.
Limits live outside the prompt. On the hosted server, set a spending policy on your wallet. On a local server, use the dry-run lock and caps, which an agent cannot switch off from a conversation.
Untrusted payment terms are checked. Before anything is signed, the server checks a gateway’s 402 terms against what it derives itself: the protocol treasury as payee, the protocol USDC mint, the protocol price and the cluster.
Verify before acting. build_verifier_calldata builds arguments only. Your contract or service calls verify().

Get started

Concepts

Access and payments

Verify and publish

Protocol

Resources

MCP server

Choose an integration

Tools at a glance

How it fits together

Safety model

​Choose an integration

​Tools at a glance

​How it fits together

​Safety model

Choose an integration

Tools at a glance

How it fits together

Safety model